<!DOCTYPE HTML>
<html>
<head>
<style>
#d1 {
  overflow:hidden;
  height:0;
}
#d2 {
  opacity:0.50196078431;
}
#d3 {
  position:absolute;
  left:0;
  top:0;
  width:100%;
  height:100%;
  background:blue;
}
</style>
</head>
<body>
<div id="d1">
  <div id="d2">
    <div id="d3"></div>
  </div>
</div>
</body>
</html>
